/*
	Name:3_2
	Copyright:Take it at will
	Author:Rodney
	Date: 
	Description:
*/
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int main()
{
    int i,n;
    float x,s=1.0,jc=1.0;
    scanf("%d%f",&n,&x);
    
    for(i=1;i<=10;i++)
    {
        jc *= i;
        s += pow(x,i)/jc;
    }
    printf("%f",s);
}

